Orcs Must Die! 2 thrusts players and their friends back into battle against terrifying mob of orcs and other monsters. With a redesigned spellbook, players have a broader range of options to build a deadly arsenal of defenses. Investing hard-earned skulls in an enormous new upgrade system  allows players to cater to their favorite methods of burning, grinding, tossing, or dismembering orcs. Orcs Must Die! 2 begins days after the ending of the original game. With the rifts closed and the magical Order dead, the War Mage finds himself suddenly thrust into a new battle against the mindless orc mob. He has a powerful, if questionable, new companion. The Sorceress, an ex-War Mage responsible for the destruction of the Order.
The game takes place a few days after the events of Orcs Must Die! The Sorceress is hiding from The Mob when mysteriously, a Rift opens next to her. She steps through, and finds herself in the Dwarven Mines, right in front of The War Mage (who now works at the mines). She enlists his help in fighting off the Orcs. The two discover that more and more rifts are opening in different locations. They decide to enter the rift and return to the Dead World.
It is revealed that the War Mage's (and, it is revealed, the Sorceress's) master had not died; he was still alive, and had opened a small weak rift to allow the Sorceress to escape and battle the Mob together. After the War Mage and the Sorceress begin to communicate with their master, he explains that he started to open the Rifts again because the world beyond the Rifts could not cope without the magic they provided.
- New Campaign – Orcs Must Die! 2 features a full campaign that you can play in single-player or with a friend in co-op. Choose to play the campaign as the War Mage, a headstrong hero who charges into dinner, or play as the more nuanced Sorceress, a new hero who keeps enemies at bay with her charm.
- More Enemies – An army of vile new creatures is set to pour through the rifts, and they’ve brought all of your favorite trap-fodder from the original Orcs Must Die! along with them!
- More Defenses – Orcs Must Die! 2 has an enormous armory of new and classic defenses, including an all new assortment of magical trinkets. Use your new spellbook to buy defenses and upgrades the way you choose to, building up your arsenal based on how you play the game.
- New Upgrade System – The Skulls system has been completely redesigned. You will always earn skulls for replaying levels, and the skulls can be spent on multiple persistent upgrades for each of your defenses.
- Endless Mode - Play against endless waves of increasingly difficult enemies.
- Weekly Challenges - Additional onslaughts that restrict the player to a certain level, traps, trinkets, and weapons.
- Main article: Orcs Must Die! 2 Soundtrack
- Owners of Orcs Must Die! will receive 10 classic maps from the first installment, featuring new enemies and co-op.
- OS: Windows XP, Windows Vista or Windows 7
- Processor: 2GHz Dual Core
- Memory: 2 GB RAM
- Graphics: NVIDIA GeForce 6800 or ATI Radeon x1950 or better with 256MB VRAM
- DirectX®: 9.0c or better
- Hard Drive: 5 GB HD space
- Additional: Broadband Internet Connection recommended for co-op play